Edge-grinding machine for lenses



Feb. 24. 1925.

1,527,594 E. M. LONG EDGE GRINDLNG MACHINE FOR LENSES Filed June 18. 1920 4 Sheets-Sheet l E. M. LONG EDGE GRI NDLNG MACHINE FOR LENSES Feb. 24, 1925.

Filed June 18.. 1920 4 Sheets-Sheet 2 Q NS W I/l;

Feb. 24, 1925.

E. M. LONG EDGE GRINDING MACHINE FOR LENSES Filed June 18. 1920 4 Sheets-Sheet 5 E. M. LONG EDGE GRINDLNG CHINE FOR LENSES Feb. 24, 1925.

4 Sheets-$heet 4 Filed June 18, 1920 IHIIJJIIIIQIWIJIHHIIIIW' or new YORK 1924).

OPTICAL COMPANY,

Application filed June is, 1920. Serial m5. 889,941.

To all whom it may concern: 7

Be it known that I, ELI M. LONG, of Geneva, in the county of Ontario, in the State of New York, have invented new and useful Improvements in Edge-Grinding Machines for Lenses, of which the following, taken. in connection with the accompanying drawings, is a full, clear, and exact description.

10 his invention relates to ments in edge-grinding machines for lenses of the class set forth in my pending application, SerrNo. 288,897, filed April 10, 1919, in so far that the main object is to bevel the marginal edge of the lens for the reception of a similarly grooved rim. a

In my pending application referred to, the axis of rotation of the rotary lens-holder is parallel with that of the grinding element to revolve the lens certain improvesired bevel to the lens.

The main object of my present invention is to reduce these difficulties to a minimum 40 bg rotating the lens-holder and lens therein whereby o posite faces of the edgeof the lens will e simultaneously brought into contact with both of the beveled grinding faces at different points in the circumferences of said beveled faces at op osite sides of the line of intersection of p anes passing throu h the axes of the grinding element and ens-holder.

In other words, I have sought to rotate the grinding element and lens in different in a plane at sub- 7 mg the and th frame.

grinder,

planes intersecting each other at an angle sufficient to cause one side of the lens to engage one of the beveled grinding faces at J of intersection, while the other side of the lens engages the other grinding edge at the opposite side of the ine of intersection, so t at the edge of the lens adjacent the grinding, surfaces will traverse greater portions of said surfaces than would be possible with the lens rotating in the same plane as ing element and results grinding, surfaces true or at approximately the desired bevel without the aid of extra truingmechanism, except'perhaps at relatively 1on intervals.

ther o jects and uses relating to specific parts of tle machine will be brought out in a the following description.

In thedrawings:

igure 1 is a top plan of an edge-grind ing machine embodying the various features of my invention.

igure 2 is a longitudinal vertical sectional view of the same mechanism showgrinding element in elevation omitting the truing device' Figure 3is an enlarged horizontal sectional view of therotary lens-holder and its driving mechanism.

Figure 4 is an enlarged side elevation of r the means for'controlling the vertical lift of the lens-holder toward and from the grinder.

Figure 5 is a longitudinal sectional view of the mechanism shown in Figure .4 except that the frame carrying the lens-holder is elevated.

Figure 6 is a top plan, partly in section, I

of a gear train for rotating the lens-holder e means for lifting the lens-holder Fi ure 7 is a detail edge view of the ratchet w eel and adjacent of the control pawl for the carriage lift.

Figure 8 is a top plan of a portion of the grinder and lens engaged therewith. 5

Figure 9 is an enlarged sectional view disks and clamping means therefor taken on line 99 Figure 2.

As illustrated, f similar relatively thin grinding disks -1- of any suitable diameter or material mounted coaxially upon a rotary horivertically by and e tically swingin the perimeter of the lens zontal shaft suitable bearings ing frame 4.-, said grinding disks being circular and having their peripheries beveled inwardly toward each other at 5- to form a V-shaped groove -5'-, the meeting faces of said disks bein held in slightly spaced relation by a circu ar disk or tiller 6- of any suitablematerial of substantially the same diameter as, or slightly less diameter than the base of the groove 5-.

The grinding disks --1 and interposed disk 6 are firmly clamped together by opposed collars 7-- and on the shaft -2-, the collar --7 being provided with a suitable hub 8 extending into central openings in both of the disks -1- -2 which is journaled in toward t e opposite collar 7- which is drawn toward the collar -7- by suitable bolts -9, Fi re 3.

The water or moistening the grinding disks is delivered by any suitable means, not shown, into an annular groove or recess 10 in the disk -7 and is carried by centrifugal force through passages -10 to and within the grindstone disks and thence by the same force through the pores of said disks to the peri heral grinding faces where it may be wipe off by a sponge or other wiper, not shown, into a trough l1- and tnence into a drain pipe l2, Figure 2, the trough --11- serving merely to catch the waste water and grinding re fuse.

The lens, as --a/-, the peripheral edge of which is to be ground, is supported edgewise coaxial with a rotary holder directly over the upper edges of the grindin disks -5-, plane 0 revolution of said disks,

said holder lbeing free to move vertically or radially asof the lens at difi'eiei'it j in its clamping position by a spring -30 portions of the edge distances from the axis of revolution are presented to the grinding surfaces, and is also free to swing laterally or axially as different portions of the edges of toric, cylindrical and other concave or convex-lenses rotating in difierent planes contact with the grinding faces. 1

The holder for the lens comprises opposed coaxial clam ing heads or collars -13- mounted en to end upon coaxial rotary shafts or spindles 1& and -14 which, in turn, are journaled insuitable bearings -15 and -l5'.-=-"on the free end of a verframe or carriage -16 which is pivote at -17- to a horizontally swinging frame -18-, the latter being pivoted at 19 to a vertically movable support --2()- carried by a bracket -2l'- on the main supporting frame -i to permit to automatically adjust itself to the beveled grinding faces of the grinder during the grinding operation and to also permit the lens-holder and its -3 on a main supportgether and also move axially,

but at an angle to the ing lens 0 amping ing the swinging supports to be adjusted vertically to compensate for varying diameters of the grinder resultin from wear or replacement by similar grin ing disks.

The adjacent ends of the lens clamping collars 13- are provided with the usual leather or equivalent pads for frictional engagement with opposite faces of the lens to cause the latter to rotate with the collars and also to reduce the liability of breakage of the lenses when clamping them between the collars.

The shaft or spindle -14 carrying one of the lens-clamping collars -13- extends entirely through the central opening of a coaxial sleeve 22- and has its inner end operatively connected to the adjacent head -13- and its outer end provided with a gear -24- forming a part of a train by which rotary motion is imparted to the shaft -14' for rotating the lens-holder.

The outer end of the spindle 14- extends some distance beyond the gear -24 for receiving and supporting a lens form or pattern -25 which cooperates with a back rest 26 to cause the lens to be ground to a similar form, said pattern being held in place by a nut 7- engaging the outer threaded end of the spindle -l4-.

The other spindle -14 's journalcd in its corresponding bearing cured in a socket in the adjacent end of the corresponding lens clamping head -13 so that the head and spindle may rotate tosaid spindle aving a collar 28 secured thereto and provided with an annular groove 29- for receiving a shifting pin presently described.

This spindle 14- is slidable axially in its bearin -15- to force the correspond head -13-- to and from its clamping position, but is normally held which is interposed between the collar -28 and a bushing 32- in the outer end of the bearing 15 as shown in Figure 3.

Suitable means is provided for withdrawspindle 14:- and its clamping head -13 from its clamping position against the action of the retracting spring 30 and for this purpose a hand lever -33- is pivoted at -34 to the periphery of the bearing 15' and has its inner and provided with a pin 35- which engages in the groove -29-- of the collar -2S and is movable in a lengthwise slot -36 in the bearing -15- as shown in Figure 1.

The axis of rotation disposed at an angle to disks, and, therefore, at of rotation of said disks, so that the grinding disks and lens rotate in different planes intersecting each other along a substantial of the lens-holder is that of the grinding an angle to the plane 1,6",504 v p a p a direct linebetween the axes'of the rotary- 90 'degrees ormore to'withdraw the lens grinder and lens-holder 'and midway befrom the grinding element and allow the tween the grinding disks, thereby causing supporting frame for't'he lens-holder to asthe ge of said lens adjacent'the grinder 'sume a position of rest in its extreme up a 5 to simultaneously contact with both of the position as shown by full lines in Figure -5. I0 beveled grinding faces at different points in The horizontally rocking frame 18 is the 'peripher of the grinder at opposite disposed in an upright position betweenforsides of said ine. a v v 7 wardly projecting lugs -20- on the frame" That is, by thisangular relation ofthe -20 and isiheld'in this position by the 10 axes of the grinder and lens-holder, one side pivotal pine or trunnions 9- one of '7 of the edge of the lens is caused to engage Y which consists of a. screw en aged in a one of the beveled grinding faces at one threaded aperture in the a jaoent lug side of the line of intersection of the planes to take 'up wear and permit the of rotation of said grinder and lens while frame l8- to be more easily and quickly it the opposite side'of the edge of the lens is assembled uponand removed from the frame 80 caused to engage the other beveled grinding .2Q-, the vertical swin ing frame -16- surface at the oppositeside of said line of being pivoted at its rear end'to or upon forintersection and inasmuch as the portions wardly projecting lugs --18'- of the frame of the beveled grinding surfaces en aged by .-1 as shown more clearly in Figure 3. v

50' the lens diverge outwardly, it is evi cut that The frame -20- is disposed in an up- 85 the edge of the lens will be beveled to conright position and isadapted to. beadjusted form to the beveled ed es of the "grinder, vertically to roduce a} conresponding adthereby causing the e geof the lens to 'justm'ent of t e lens-holder f, to conform to y traverse ractically the entire areas of the varying diameters of the grintlensaid frame 26 beveled aces of both grinding elements, being gu ded in its vertical adjustment, and 90 and, in turn, will keep the grlndlng'surfaces old in operative position byjnpr ight guide more olosel to their original lfvel as they rods 40+ and .-40- in spaced relation wear away y contact with the ens. transversel of the machine -.and, eachpass- Under t ese conditions, it is evident that ing through vertically registerin apertures 80' the proper'an le .of the beveled grinding", in said frame, said rods vbeing supported in. o

, surfaces will e maintained for ajniuc'h; suitable hearings or lugs 41 and -41?- longer period of time wlthout regrmdu igfior on the br bket-2la suflicient distance trumg and that both edges'ofthe lens will, below an above, the frame 20 toallow e ground more rapidly andmo're' even lyflforfithe sired vertical adjustment of said by reason'of the longer line's of cont act b tweenjthe bear1ngs,' one of said 100 the grinder: than 1 would be possible-1f the; guiderotis, as -v l0 "beingprovided with enses" were revolved in the;same' planeEasjathreaded portionengaging in a that'of thegrmdery 'threadedaperturef "in the lower side Infltoricand other-spherical orjcylindi'icall of-the' frame *QQ andproVided at its k lenses-,particnlarly those of elliptical shape, 7 "lowgrigf end' withan 'angular'j-hedd 105 I dziferentg por'tions of the edges thereof are tea tedto,be:engagedcbyasuitable wrench disposed in different.planes -'and;; -qatY- dif-g j rboth"er;:tbol for rotating the. screw and ferent distances from t e axis of rotation, rtlierebyfefiecting ythe desired. vertical, ad-

and in order that the lensfmay' automa'ti "'us't'r'nen't of the frame and lens- 1 45 cally adjust itself to bring these ydifiere holder-carried th eby through t e medium 110 e of the fr mes 6-- and -18-.'

portionsinto roper grinding. relation tot grinding sur aces, the supporting frame as The 1 tarygrinder and lens-holder are -16-, for the lens-holder is aflorded'a ree preferably power driven and for this purvertical and lateral rocking moveme t as pose a/ shaft -45- is journaled in suitable previously explained while the edge 0 the/ hearings on the bracket -2l and provided 11 lens is held against the grinding surfaces with a pulley -47- adapted to be conby theweight of the frame and lens-holder nected by a beltf48-- to any available thereon. I '1' sonrceof power, not shown, said shaft being This support -16- preferably compi ises also provided. with another pulley -49,

a pair of oppositely disposed arms '-16- which is connected by a belt 50- to a 12 carrying the earings -15 and l5. in pulley 5l on the supporting shaft 2- spaced relation at opposite ends of the lens for rotating thegrinder. m clamping heads -13- and rigidly con- A gear worm -52- is secured to the nected to each other by a cross-bar -37- shaft -45- at substantially the longitu-j so that both bearings carrying the lens dinal center of the machine or midway be 1 holder may be caused to movevertically in tween the pullevs -47- and -49- and unison, the crossbar -37- also serving as engages a gear -53- on an upright shaft a handle by which said frame may be rocked 54, which is journals-d in vertically I upwardly and rearwardly at will about the spacedv bearings -55-- and 55-' on the 0 axis of the pivots '-'17- through an arc of bracket. 2l, the worm gear -53 bein'g lfiu able hearings in the arms -16'- of the vera train of,

" worm gear -57,

, within the frame -.-20

rovided with a vertically elongated hub aving a Laser worm -56- meshing with a which, together with a gear -57'- are rotatably mounted and preferably up.-

on a shaft v I A cross shaft --59 is journaled' in suitspur tically rocking frame --16 and is driven by the gear 57 through the medium of inthis instance three, gears -60-, one of which is secured to the shaft -'-59- while the others are secured, re-

between and-parallel with the cross shafts --61-' and -62. and 'are' so related to the pitch diameters of the gears --60 on said shafts as to allow the frame -16'- to swing upwardly from a substantially horizontal to a substantially vertical position of temporary rest and during such movement to cause the gear on the shaft 59 to disengage from its companion gear -60 on the shaft 62 ,for automatically stoppingthe rotation of the M lens-holder and permitting the finished lens tobe removed and replaced by others to be finished, rotary motion being transmitted from the cross shaft 59-- to another cross shaft --63- and thence to the gear 24- through the medium of a gear --63'- for rotating the lens-holder.

-, Pattern rest aalj'ustmen-t.

The lens to bebeveled by the grinder previously described is usually cut or groun to approximately the desired form and size so that a relatively small number of turns of the lens against the rinder is sufficient to produce the desired bevel, and one of the objects of my present invention is to provide means whereby the lens-holder. will be gradually and automatically lowered toward the grinder when it has been rotated a suflicient number of turns to produce the necessary bevel entirely around the periphery of the lens and for this purpose, the rest 26 is supported upon one end of a lever 64' which is fulcrumed intermediate its ends at 65-- upon "a portion of the horizontal rocking frame -18- to rock verti- (See Fig.4.)

call lilo other end of the lever is provided with a bearing'-66 adapted to be engaged by a rotary. 'cam--67- which is mounted upon a horizon l shaft or stud --68 on may rotate together, the shaft -59 provided the. frame ----18- and is also secured to a coaxlal rotary ratchet wheel -69- on the same stud so that the cam and ratchet wheel being 7 at one end with an eccentric pin .-70- upon which is journaled one end of a pawl -7 1- having its other end adapted to successively en age the teeth of the ratchet wheel -69- as t e pawl is reciprocated by the rotation of the eccentric -70 for rotating the cam step by step in the direction indicated by arrow :0, Figure --4-.

That is the cam -67 will be rotated one tooth space of the ratchet wheel 69 at each revolution of the shaft -59- so that if there were forty teeth in the ratchet wheel -69 it would be rotated one complete revolution at each forty revolutions of the eccentric '70- and if the ratio of speed between the lens-holder and eccentric is one to two, the lens-holder would be rotated twenty revolutions at each revolution of the ratchet wheel and would be sufiicient to grind the edge of the lens to the desired bevels at one revolution of the ratchet wheel or At the beginning of each revolution of the cam, its high point is engaged with the bearing -66, and it, therefore, follows that as the cam is rotated, the lens rest 26, together with the overlying portion of the frame or carriage -16 which supports the rotary lens-holder and pattern, will be gradually lowered, thereby causing the edge of the lens to be gradually beveled on both sides during one complete revolution or cycle of operationof the cam, or until the lowest point ofsaid cam is registered with said bearing, at which time, the carriage 16- will be automatically rocked upwardly to a position of temporary rest,

' thereby withdrawing. the lens-holder upwardly from the grindstone about the axis of the pivots -17- and simultaneously disengaging the gear connections between the spindles 59- and 62- to stop the rotation of the lens-holder and permit the withdrawal of the finished lens.

This upward movement of the carriage 16 is also utilized to shift the cam -67- from its low point to its high point of engagement with the bearing -66 by reason of the engagement of the pawl 71 with the ratchet -69- as the carriage -16- is rocked upwardly.

Uam'iage lift.

The inner end face of the ratchet wheel -69 is provided with a notch or recess -7Qr for receiving sliding bolt 73- as the adjacent end of a the cam approaches 7 jun ill]

the end of each cycle of rotation or when the low point of the cam is engaged with the bearing -66, said bolt being springpressed toward the ratchet wheel by means of a lever -74- and a spring -75 so as ed upon the front end of a shaft -94- havto normally ride a ainst the inner face of ing its rear end connected by a worm and the ratchet wheel uring the cycle of rotagear -95 to the main driving shaft tiori and into the recess at the end of said as shown more clearly in Figure eye 0. '1. p -7 The lever -74- is fulcrumed on the It is evident, however, that the various frame -18- near the bolt -73- to swin mechanisms for regulating the feed of the horizontally independently of the horizonta lens to the stone and for raising the carriage swinging movement of said frame and has for the lens-holder may be varied in man 10" its lon r arm provided with an upstanding ways, and, therefore, I do. not wish to limit pin 6 for engaging and rocking anmyself to the specific structural details other horizontal swinging lever -77- into shown and described. the path of a revolving lifting member What I claim i's: -78 on the shaft -62- against the action 1. In a lens-edge-beveling machine, a ro- 5 of a retracting spring -79 which is contary grinder having an annular groove, and $0 siderably lighter than the spring -75. means for rotatably supporting a lens edge- This lever -77-- is pivoted to the under wise diagonally across the groove with its side of the cross-bar 37 on the frame edge contacting at one side only of its axis I ;1 6-- and, it, therefore, follows that when of. rotation against opposite walls of the go It is moved laterally into the path of the groove for slmultaneously beveling both continuously rotating member -'78--, the corners of the edge of the lens. frame -16- will be rocked upwardly 2. In a lens-edge-beveling machine, a roand the gear on theshaft -59- dista grinder having pposed beveled faces, enga ed from that on the shaft -62-t, an means forrotatablysupporting alens at u whic disengagement takes place when the an acute angle the axle of the grinder and frame 16- assumes a position slightly its edge contacting at one side only of its beyond a vertical, where it tem orarily rests axis againstboth of said beveled faces for untilreturned by hand. (See ig. 15.) simultaneously beveling both corners of the During this upward movement of the edge-of the lens.'

to frame -16- the pawl -71- which is piv- 3.. In a lens-edge-beveling machine, a m

oted thereto, is shifted rearwardly and tary grinder havmg an annular groove, and causes a corresponding rotary movementof means for rotatably supporting a lens .ed the ratchet wheel 69 suflicient to shift wise diagonally to and against opposite the point of engagement of the cam 67-- walls "of thegroove o for simultaneousl with the bearing 66 from the low point beve'ling both earners of the edge of the lens, 109 I to the high or starting point and at the same"'said lens supporting means being movable time, the bolt -73- is forced out of them transversely of the plane of rotation of the cess '-72- by means of a cam, face at grinder-and actuated-by contact of the edge one side of said recess. of the'lens with opposite walls of the groove. 40 As the frame -16- is rocked upwardly, 4. In a lens-edgebeveling machine, a ro- 10 the lever '-77- is withdrawn from engage tary grinder having opposed beveled faces, ly and means for rotatably supporting a. lens held in lifting engagement with the member edgewise diagonally to and against both of --78- against the action of the spring said beveled faces for simultaneously bevel- I I 45 -79 by the weight of the frame until the mgboth corners of the edge ofithe lens, said 1 latter assumes a substantially upright posilens-supporting-means :being movable about tion, at which time, the lifting member an axis parallel with the lane of rotation of --78- and lever -77-- which swing in dift e g'inder and actuatedlby' contact of the ferent arcs are disen aged to allow the lever edge .of the lens with the beveled faces of so -77- tobereturn by the spring --79--. the inder. p I,

The finished lens is then removed and re- 5. n a machine for beveling the edges of placed by another one to be finished, after lenses, the combination of 'a rotary grinder which the frame -16 is lowered by hand having opposed beveled faces, arotary lensready for a repetition of the operations preholder and a su port therefor hinged to II! viously descri ed. swing toward an from and transversely of A suitable truin device for keeping the the periphery of the grinder by contact of beveled edges of t e grinder, at the desired the lens with said beveled faces, said lensangle is mounted upon the front portion of holder being journaled on the support to the machine and is provided with a pair of rotate about an axis diagonally to the plane to cutting bars 90- of carborundum, or of rotation of the grinder for holding the other suitable material, adjustably mounted lens edgewise against both of said beveled upon resilient supports -9lcapable of faces. lateral vibratory movement which is pro- 6. In a machine for beveling thetedges of l duced by means of an eccentric 92 and lenses, a rotary grinder having opposed u a pitman -93-, and eccentric being mountbeveled faces, means for rotatively support to compensate for ing a lens edgewise diagonally to and against both of said faces and movable transversely of the plane of rotation of the grinder by contact with the edge of the lens with said beveled faces, means for rotating the'lens and means actuated by the second named means for moving the first named means away from the grinder when the lens has been rotated a predetermined number of revolutions.

7.'In a lens edge beveling machine, a grinding element having opposed abrasive faces, a rotary lens holding element for supporting a lens edgewise diagonally across and against both of said faces, the engagement of the lens with said faces causing one element to automatically shift in the direction of the axis of the lens holding element variations in the planes of rotation of different portions of the edge of the lens.

8. In a lens edge beveling machine, a rotary grinding element having opposed beveled faces, and a rotary lens-holding element having its axis extending diagonally across the face of the grinder and supportof the lens, .ing element, and means actuated by the last ing a lens edgewise against both of said faces, one element bein movable axially relatively to the other e ement by the engagement of the edge of the lens with the beveled grinding faces when different positions of the edge of the lens rotate in different planes.

9. In a lens edge beveling machine, a grinding element having opposed abrasive faces, a rotary lens holding element for supporting a lens edgewise diagonally across and against both of said faces, the engagement of the lens with said faces causin one element to automatically shift in the irection of the axis of the lens holding element to compensate for variations in the planes of rotation of different portions of the edge means for rotating the lens holdnamed means for moving one of the elements away from the other element'asufiicient distance to disen age the lens from the grinder at the end 0 a predetermined number of revolutions of the lens-holding element.

10. In an edge grinding machine for lenses, a rotary lens holder, and a rocking support therefor adapted to move the lens holder toward the grinder as the edge of the lens is ground away, a rotary driving element, a gear train partly mounted upon said rocking support for transmitting motion from the driving element to the lens holder while the lens is in contact with the grinder and means actuated by said gear train at the end of a predetermined number of revolutions of the lens holder for rocking said upp t and 1 ;@a s n aw y r the grinder, said rocking oft being: so

related to' thei gear tram ai Q,

train from other parts parts of the gear support is rocked away thereof when the from the grinder.

11. In an edge grinding machine for lenses, the combination of a grinder rotatable about a horizontal axis and provided with opposed beveled grinding faces, means for rotatably supporting a lens edgewise diagonally across and against both of said beveled faces, and driving means for the rotary grinder and lens holder said supporting means being free to move in reverse directions transversely of the grinding faces by contact of the edge of the lens therewith.

12. In a machine for beveling the edge of a lens, a grinder rotatable about a horizontal axis and provided with opposed beveled faces, a support for a lens-holder movable about a vertical axis, a lens holder mounted on said support to rotate about-an axis diagonal to the plane of rotation of the grinder and supporting a lens edgewise diagonally across and against both of said bevel faces, the engagement of the edge of the lens with the bevel faces serving to shift the support about its vertical axis to compensate for variations in the planes of rotation of different portions of the edge of the lens.

13. In an edge grinding machine for lenses, the combination of a rotary grinder having opposed beveled grinding faces, means for rotatably supporting a lens edgewisc diagonally across and against both of said faces, said means being free to move radially and axially of the grinder and actuated in both of the last named directions by contact of the lenses with the beveled grinding faces, driving means for rotating the lens, a stop for limiting the movement of the lens supporting means toward the axis of the grinder and means actuated by said driving means for gradually moving the stop toward the axis of the grinder as the lens is ground away.

14. In an edge grinding machine for lenses, the combination of a rotary grinder having opposed beveled grinding faces, means for rotatably supporting a lens edgewise diagonally across and against both of said faces, said means being free to move radially and axilly of the grinder and actuated in both of the last named directions by contact of the lens with the beveled grinding faces, driving means for rotating the lens, and means actuated by said driving means for stopping the rotation of the lens at the end of a, predetermined number of revolutions thereof.

15. In an edge grinding machine for lenses, the combination or a rotary grinder having opposed beveled grinding faces, rneans gfor rotatablysupporting a lens edgewi se diagonally ;,acrossa and against both of sa d faces, :said ;:i-me ans being free to move loo ' ing means away radially and axially of the grinder and actuated in both of the last named directions by contact of the lenses with the beveled grinding faces, driving means for rotating the lens, a stop for limiting the movement of the lens supporting means toward the axis of the grinder, means actuated by said driving means-for gradually moving the stop toward the axis of the grinder as the lens is ground away, and means actuated by said driving means for moving the lens suppoitfrom the grinder at the end of a predetermined number of revolutions.

16. In an edge grinding machine for lenses, the combination of a grinder rotatable about a horizontal axis and provided with opposed beveled grinding faces, means for rotatably supporting a lens edgewise diagonally across and against both of said faces directly over the axis of the grinder, said supporting means being movable radially and axially tact of the edge of the lens with the grinding faces, and driving means for rotating the lens.

17. In an edge grinding machine for lenses, the combination of a grinder rotatable about a horizontal axis and provided with opposed beveled grinding faces, means for rotatably supporting a lens. edgewise diagonally across and against both of said faces directly over the axis of the grinder, said supporting means being movable radially and axially of the grinder by 'contact of the edge of the lens with the grind-1 ing faces, driving means for rotating the lens, means for limiting the movement of the lens supporting means toward the'axis of the grinder, and means actuated by the driving means for adjusting sa1d limiting means a definite amount-at each revolution of the lens to allow the lens means to move gradually toward the grinder,

supporting the axis'of 18. In an edge grinding machine for of the grinder by con a predetermined lenses, thecombination of a grinder rotatable about a horizontal axis and provided with opposed beveled grinding faces, means for rotatably supporting a lens diagonally across and against both of said faces directly over the axis of the grinder, supporting means being movable radially and axially of the grinder by con tact of the edge of the lens with the grind ing faces, driving means for rotating the lens, and means actuated by said driving means for moving the lens supporting means away from the grinder at the end of a preiietermined number of revolutions of the ens.

19. In an edge grinding machine for lenses, the combination of a grinder rotatable about a horizontal axis and provided with opposed beveled grinding faces, means for rotatably supporting a lens edgewise diagonally across and against both of said faces directly over-the axis of the grinder, said supporting means'bei g movable radially and axially of the grinder by contactof the edge of the lens with the grinding faces,

' t is for limiting ,the movement of the lens supthe axis of the by the driving porting means toward grinder, means actuated means for adjusting said limiting means a definite amount at each revolution of the lens to allow the lens supporting means to move gradually toward the axis of the grinder, and means actuated by the driving'means for moving the lens supporting means away from the grinder at the end of movement of revolutions of the lens.

In witness whereof I have hereunto set my hand this 10th day of June, 1920.

ELI MAYNARD LONG, Witnesses: g V

H. E. CHASE, R. G. CARROLL,

edgewise 

